Heating device for rotary furnaces



Dec. 25, 1934. H, GARREAU 1,985,566

HEATING DEVICE FOR ROTARY FURNACES Filed Dec. 11, 1931 37 A g In): 1777f.

4O Herr/'4' Gar-reaw,

Patented Dec. 25, 1934 UNITED STATES 1,985,566 HEATING DEVICE FOR-ROTARY FURNACES Henri Garreau, Paris,

, firm Belgium Rotary Furnaces Limited,

France, assignor to the Brussels,

Application December 11, 1931, Serial No. 580,438 In France December 24, 1930 3 Claims.

This invention has for its object improvements in and relating to heating devices for rotary furnaces.

In my copending specification No. 376,646 filed 5 on July 9, 1929, has been described a device for melting ores utilizing a furnace the heating of which is obtained by means of powdered coal the combustion of which is effected outside the furnace at the extremity of a burner arranged to permit the feeding of pulverized carbon and air, due to the arrangement of a rotary joint.

According to the present invention, the whole of the burner and its chamber comprises a jacketing, which is for example metallic, intended to be connected rigidly to the metal covering of the furnace and comprising a refractory interior lining whereby, in the interior of the whole device is provided a combustion chamber disposed outside the furnace, limited at its exterior extremity by tuyres or bars of material such as for example carborundum whilst the other extremity is in direct communication with the interior of the heating furnace, with a View to ensuring in a more certain manner, the taking place of the whole of the combustion outside the furnace.

Reference is now directed to the accompanying drawing showing a preferred embodiment of my invention, wherein:-

Fig. l is an axial section of the burner in the position which it occupies at the end of the furnace which it is designed to heat, such furnace being however omitted, its extreme end only being shown on the drawing, and

Fig. 2 is a section on line II-II of Fig. 1.

Fig. 3 is a transverse section on line III--1II of Fig. 1.

Fig. 4 is a detail in section of a safety fusible door hereafter referred to.

The burner comprises a jacket 28, for example of sheet metal intended to be connected to the covering 29 of the furnace and having a cylindrical external shape. In the interior of the jacket 28 there is arranged a refractory lining 30, for example of earthenware similar to that which constitutes the interior lining of the furnace and in which there are provided apertures such as 31 intended to facilitate the lighting and provided with removable obturators 32 constituted for example by refractory bricks.

The right-hand end of the burner, as shown in Figs. 1 and 3, is provided near the lining 30 with a double row of refractory blocks 35 and 36 which hold bars 37 of a material such as carborundum which constitutev a kind of grate as more particularly shown in Figs. 2 and 3.

These bars could be interconnected or single while it is preferable to have them constituted as a whole grate for constituting easier means of fitting.

The expansion chamber 42 which is located on the right-hand of grate 37, as shown, is limited by a deflecting plate 33 which occupies the central part of said chamber 42 in rear of the ad- 10 mission aperture 34 which is connected with the device for feeding the mixture of fuel and air (not shown on the drawing).

Due to this arrangement, such mixture of coal and air is admitted towards the grate 37 as 15 shown in Fig. 1 and Fig. 2 by the arrows.

In front of the bars 37, there are provided apertures 45 provided with convenient obturators 46 which are designed for allowing access and repairs of the grate 3'7.

The combustion chamber 38 located between grate 3'7 and chamber 39 has preferably, as indicated in the drawing, a flaring form which may, in transverse section, be of rectangular polygonal, circular or other form.

Before the bars 37 a safety device is provided, constituted for example by a tubular refractory fitting 43 (Figs. 2 and 4) supporting a changeable operculum or cover 44, constituted by a plate of aluminium or other metal alloy, the metal alloy entering into a state of fusion when, due to an accident or any other cause, the combustion takes place in front of the grate 37, that is to say between this grate and the expansion chamber 42, thus giving the necessary warning. The form of this fusible operculum or cover 44 as well as its mounting is indicated here solely by way of example, and may be varied according to desire.

The tube 43 (Figs. 2 and 4) which carries the safety device is embedded in the lining of the burner or located in a convenient channel provided in one of the bricks 35.

The tube 43 is radially located in the burner for instance in the position shown in dotted-anddash lines in Fig. 1.

The refractory blocks are preferably separated from the jacketing 28 of the burner by a lining 40 having low heat-conducting properties.

The mixture of powdered coal and air is 50 brought through inlet 34, impinges and passes baffle 33 in chamber 42 through the grate 3'7 which is considerably heated so that said mixture of powdered coal and air considerably heated in said grate is put into fire on the left hand side of said 55 the other end of the chamber having direct com-' munication with the interior of said heating furnace, an expansion chamber adjacent and exterior to said bars, and means for leading fuel to said expansion chamber.

2. A burner as set forth in claim 1 wherein said bars are formed of carborundum, refractory blocks retaining said bars in position and a lining interposed between said blocks and the burner jacket.

3. A burner as set forth in claim 1 wherein a replaceable fusible alloy is located in a tubular support positioned within said expansion cham- 10 her.

HENRI GARREAU. 

